fix stuck 'Agent is thinking' + flip activity to old-to-new

- AgentIndicator now shows only during stream or when running tools exist
  (not on session status=executing which never cleared)
- Activity timeline: oldest-first ordering (reads top-to-bottom naturally)
- Removed unused liveStatus derivation and currentTask import from Chat
- Plan: Phase A+B+C for activity gaps + plan-approve-once policy

web/src/lib/stores/activity.ts

@@ -127,8 +127,8 @@ export const activityLog = derived([messages, planSteps, currentTask], ([$msgs,
     })
   }
 
-  // Sort newest first
-  entries.sort((a, b) => b.timestamp - a.timestamp)
+  // Sort oldest first
+  entries.sort((a, b) => a.timestamp - b.timestamp)
 
   return entries
 })

web/src/pages/Chat.svelte

@@ -1,7 +1,6 @@
 <script lang="ts">
   import { messages, streaming, connectionState, currentSession, sendMessage, cancelStream, reconnect, error, chatErrors, dismissError } from '$lib/stores/chat'
   import { activityLog } from '$lib/stores/activity'
-  import { currentTask } from '$lib/stores/workspace'
   import SessionRail from '$lib/components/SessionRail.svelte'
   import TaskContextPanel from '$lib/components/TaskContextPanel.svelte'
   import InlineApproval from '$lib/components/InlineApproval.svelte'
@@ -103,8 +102,6 @@
     if ($streaming) return
     sendMessage(q)
   }
-
-  const liveStatus = $derived($currentTask?.status ?? ($currentSession ? 'active' : null))
 </script>
 
 <div class="flex h-full min-h-0">
@@ -152,7 +149,7 @@
           </div>
         {/each}
         <AgentIndicator
-          active={$streaming || liveStatus === 'executing'}
+          active={$streaming || $activityLog.some((e) => e.status === 'running')}
           lastActivity={$activityLog.find((e) => e.status === 'running') ?? null}
           error={$error}
         />